Yarn changing and feeding arrangement for circular knitting machines



March 17, 1970 R. SCHMIDT 3,500,663

YARN CHANGING AND FEEDING ARRANGEMENT FOR CIRCULAR KNITTING MACHINES Filed April 1, 1968 FIG. '7

I I l l x 1 l I United States Patent 3 500 663 YARN CHANGING AND FEEDING ARRANGE- MENT FOR CIRCULAR KNITI'ING MACHINES Richard Schmidt, Stuttgart-Vaihingen, Germany, asslgnor to Franz Morat GmbH, Stuttgart-Vaihingen, Germany Filed Apr. 1, 1968, Ser. No. 718,315 Int. Cl. D04b 15/54, 23/22, 27/02 US. Cl. 66-439 Claims ABSTRACT OF THE DISCLOSURE A set of yarn guides for feeding different yarns to the needles of a knitting machine at a knitting station, are moved together by electromagnetic selector means between a plurality of positions in which one selected yarn guide is operative, and can be moved by electromagnetic actuating means to an advanced position for feeding the respective yarn.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION It is an object of the invention to improve the yarn changing and feeding arrangements according to the prior art, and to provide a reliably operating arrangement for placing selected yarn guides in a yarn feeding position.

Another object of the invention is to carry out the selection of a yarn guide by a first electromagnetic means, and the actuation of the selected yarn guide by second electromagnetic means.

Another object of the invention is to provide a single electromagnetic means for actuating any one of a plurality of yarn guides so that it is not necessary to'provide an actuating magnet for each yarn guide. I

With these objects in view, the present invention relates to an improved yarn changing and feeding arrangement for supplying different yarns, which may have different colors, to a knitting station of a knitting machine.

One embodiment of the invention comprises electromagnetic selector means having a movable selector member, a set of yarn guides mounted on the selector member for movement with the same between a plurality of positions in which a selected yarn guide is located in anv operative position, and also mounted on the selector member for movement relative to the same in the operative position between a normal position and an advanced position for feeding a yarn; and electromagnetic actuating means for moving the selected yarn guide, which is in the operative position, to the advanced position.

The selector member moves along a first path with the yarn guides, while the yarn guides move relative to the selector member along a second path transverse'to the first path to and from the advanced position. The electromagnetic actuating means includes a movable actuating member located in the second path for pushing the selected yarn guide to the advanced position, Each yarn guide is preferably provided with a spring by which it is returned to its normal position when selection of another yarn guide is required by the program. The im- 3,500,663 Patented Mar. 17, 1970 pulses for energizing the electromagnetic selector means and the electromagnetic actuating means are produced by switches respectively connected in series with the windings of the electromagnetic selector means and actuating means and being opened and closed by program control means, such as a tape haivng perforations which are sensed by feeler means, or transparent spots which are sensed by photoelectric sensing means.

In the preferred embodiment, the electromagnetic selector means includes a set of individually energizable windings having the same height, and the selector member has a magnetizable core portion of the same winding height. When the windings are successively energized, the core portion is moved in steps so that the selector member with the yarn guides moves between a plurality of positions for placing the selected yarn guide in an operative position in the path of movement of the armature of the actuating electromagnetic means. The remainder of the selector member, which supports the yarn guides, is preferably made of a non-magnetizable material.

Preferably, each yarn guide has a catch projection cooperating with a single stationary catch projection located in'the second path so that the selected yarn guide can be arrested in its advanced operative position in which it feeds a yarn to the knitting needles. When all yarn guides are moved transversely by the selector member along the first path, the catch portion of the advanced and operative yarn guide is released from the stationary catch so that the previously operative yarn guide is returned to its normal inoperative position by its spring.

In a preferred embodiment of the invention, all movements of the yarn guides to the advanced position are effected by the actuating electromagnetic means, while each yarn guide has a spring for returning it to the normal position. Only short enrgizing impulses are required, so that it is not necessary to maintain the windings of the electromagnetic means energized for a considerable period of time which may cause overheating.

It is an advantage of the construction of the invention that the yarn guide having the selected yarn is preselected before the actuation of the yarn guide and its movement to the yarn feeding position takes place at each knitting station of the knitting machine.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a fragmentary schematic developed elevation illustrating an embodiment of the invention provided in a circular knitting machine; and

FIG. 2 is a fragmentary schematic plan view, partly in horizontal section, illustrating the embodiment of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT A circular knitting machine of conventional construction is schematically illustrated by cylinder needles N mounted on a needle cylinder Z whose top is covered by the dial cam plate R. A carrier C in the region of the knitting station supports cutting means and clamping means, not shown, for the yarns F. i

The stationary dial plate R supports a bearing 9 in whose cylindrical bore a shaft is mounted which has a non-magnetizable portion 7, and a metal portion 6. A pin or key 9a projects from shaft portion 6 and is guided 3 in a groove 9b of bearing 9 so that shaft 6, 7 cannot turn in the bearing, and is mounted in the same for recti: linear movement along a first path. A set of coils or windings 201 to 205 of circular shape is also supported on the dial plate R and forms an inner cylindrical space in which a magnetizable core portion 8 is located. Core portion -8 is fixedly secured to the non-magnetizable portion 7, and has an axial height equal to the axial height A of each of the windings 201 to 205. Each winding is connected with a switch, only switches 302 and 303 of windings 202 and 203 being shown for the sake of simplicity. When winding 201 is energized, the core portion 8 will be in the illustrated position, and when winding 202 is energized, and winding 201 is deenergized, the core portion 8 will move one step into winding 202. By successively energizing the windings, core portion 8 can be placed in a plurality of positions so that shaft 6, 7, 8 moves between a plurality of positions to a selected position determined by the operation of the switches which are program controlled.

Shaft portion 6 projects beyond the circle formed by the cylinder needles N and has a set of bores 6a in each of which a yarn guide is mounted for movement transverse to the path of movement of shaft 6. In the illustrated embodiment, five windings and five yarn guides 1 to 5 are provided. In order to provide better guidance, five bushings B are aligned with bores 6a so that each yarn guide passes through a bushing B and a bore 6a and has a rear end portion with an abutment 1a to 5a. Springs 101 to 105 have ends abutting the abutments and shaft 6 and urging the yarn guides to the normal position in which yarn guides 1 to 4 are shown in FIG. 2. The front ends of the yarn guides have eyes E through which different yarns are threaded which are supplied by separate bobbins, not shown. Yarn guides 1 to 5 are spaced equal distances along shaft 6, corresponding to the height A of each winding 201 to 205 and to the length of a step which core portion 8 is moved. In the position of FIG. 2, yarn guide 5 is in an operative position, but by successive energization of windings 202 to 205, all yarn guides are moved in steps until the position schematically indicated by the broken and chain line in FIG. 2 is reached in which yarn guide 5 is in the inoperative position 5', and yarn guide 1 is in the operative position.

Any yarn guide which is in the operative position, can be moved from the retracted normal position in which it is urged by the respective spring 101 to 105, to the advanced feeding position in which yarn guide 5 is shown in FIG. 2. For example, if by energization of windings 202 and 203 by successive closing of switches 302, 303, core 8 would be moved to a position located within winding 203 so that shaft 6, 7, 8, which constitutes a selector member, would place the selected yarn guide 3 in the operative position.

Any yarn guide in the operative position is aligned with an actuating member 12 having a magnetizable armature portion 11 and forming part of electromagnetic actuating means 10. The actuating armature member 11, 12 is biased by spring 13 which is secured to a stationary frame part so that actuating member 12 remains in the illustrated inoperative position until the winding of the electromagnetic actuating means is energized so that the actuating member 12 is advanced against the action of spring 13 and engages the rear abutment 1a to 5a of the respective selected yarn guide in the operative position so as to move the yarn guide from the normal position to the advanced position in which yarn guide 5 is shown in FIG. 2.

It will be seen that any yarn guide can be moved to an operative position aligned with electromagnetic actuating means 10, 11, 12, and when in the operative position, can be moved to an advanced position for feeding a selected yarn to the needles of the knitting machine. A switch 10a is connected in series with the winding of the electromagnetic means 10 and is closed and opened in accordance with a program so that electromagnetic means 10 is energized after the selection has been carried out by energization of selected windings 201 to 205 by closing the respective switches 301 to 305.

A stationary catch 207 is located below the plane of the yarn guides in the path along which the operative yarn guide is moved by the actuating electromagnetic means 10, 11, 12. Each yarn guide has a downwardly projecting catch 206, and the catch of the operative yarn guide, for example yarn guide 5 in FIG. 2, moves over the slanted back of catch 207 during advance of the respective yarn guide, and assumes the arresting position shown in FIG. 1 when the operative yarn guide has been moved by electromagnetic means 10, 11, 12 to the advanced position for feeding its yarn to the needles. Either catch 206 or catch 207 can be resilient, but it is preferred to make the stationary catch 207 resil-' ient so that it yields when catch 206 passes over'its slanted back, and snaps behind thesteep rear faceof catch 206 when the respective selected yarn guide has arrived in its advanced position, as shown for yarn guide 5 in FIG. 1.

When another yarn is to be used for the continuing knitting operation, and shaft 6, 7, 8 is shifted with all yarn guides until another selected yarn guide is located in the operative position, catch 206 of the previously operative yarn guide moves to a position transversely spaced from the catch 207 so that its spring, for example spring 105, can retract the respective yarn guide to its normal position. The catch 206 of the newly selected yarn guide is at first located at the end of its guide bushing B- behind catch 207, and when actuating electromagnetic means 10, 11, 12 is operated to push the newly selected yam guide to its advanced position, its catch 206 passes over the slanted back of catch 207 and abuts the same under the action of the compressed spring thereof so that the respective newly selected yarn guide is held in the advanced feeding position after the energization of the winding of actuating electromagnetic means 10 has been terminated so that a short impulse is sufiicient for moving a selected yarn guide to its advanced feeding position, and the power of electromagnetic means 10 is not required for holding the selected yarn guide in the advanced position.

Summarizing, by selectively energizing and deenergizing selector magnet windings 201 to 205, selector member 8, 7, 6 is moved along a first path together with yarn guides 1' to 5 until a selected yarn guide is located in an operative position aligned with actuating member 12. When actuating electromagnetic means 10, 11, 12 is energized, actuating member 12 advances along a second path transverse to the first path and pushes the respective yarn guide along the second path to an advanced feeding position in which its spring 101 to 105 is compressed without being able to return the yarn guide since the same is arrested by arresting means 206, 207. Electromagnetic means 10, 11, 12 can be immediately deenergized.

When the next selection is carried out, arresting catch 206 of the operative and advanced selected yarn guide is separated from the stationary catch 207 so that its spring returns the yarn guide to its normal position.

The windings 201 to 205 and 10 are energized and deenergized by opening and closing switches connected in series with the same in a well known manner under the control of a tape or other program means. For example, a transparent tape may have tracks with transparent dots or perforations sensed by a suitable sensing means operating relays controlling the switches which are connected in series with the windings of the apparatus. The program recorded in coded form on the tape corresponds to the desired knitting pattern. 7

Whenever a yarn guide has finished its operation and has been shifted out if its operative position and returned from the advanced feeding position to its normal position, cutting means, not shown, cut off its thread, and clamping means to hold the cut-oif thread until the respective yarn guide is again moved to the operative position. These devices are known to those skilled in the art and not an object of the invention, and consequently are not illustrated in the drawing.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of yarn changing and feeding arrangements differing from the types described above.

While the invention has been illustrated and described as embodied in a set of yarn guides selectively movable to an operative position by electromagnetic selector means, and moved in the operative position by electromagnetic actuating means to an advanced feeding position, it is not intended to be limited to the details shown, since various modificaions and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Yarn changing and feeding arrangement for a feed station of a knitting machine comprising, in combination, electromagnetic selector means having a selector member mounted for movement along a first path; a set of yarn guides mounted on said selector member spaced along said first path and for movement with the same between a plurality of positions in which a selected one of said yarn guides is located in an operative position, said yarn guides being also mounted on said selector memher for movement relative to the same in said operative position along a second path transverse to said first path between a normal position and an advanced position for feeding a yarn guided therein at the knitting station to the knitting instrumentalities; and actuating means for moving the selected yarn guide in said operative position along said second path to and from said advanced position, and including actuating electromagnetic means.

2. An arrangement as claimed in claim 1, wherein said electromagnetic selector means includes a set of in dividually energizable windings disposed along said first path and having the same height, and wherein said selector member has a magnetizable core portion having substantially said height so that by successive energization of said windings said core portion and said selector member with said yarn guides is moved between said plurality of positions distances corresponding to said height for placing said selected yarn guide in said operative position.

3. An arrangement as claimed in claim 1, wherein said actuating means includes a set of spring, means connected with said yarn guides, respectively, for urging the same into said normal position, and wherein said actuating electromagnet means includes an actuating armature member movable along said second path for moving said selected yarn guide in said operative position to said advanced position.

4. An arrangement as claimed in claim 3, comprising arresting means for arresting said selected yarn guide in said operative and advanced position while feeding a yarn so that said actuating electromagnetic means can be shortly energized, and for releasing said yarn guide when moved by said selector member out of said operative position so that the respective spring means returns said yarn guide to said normal position.

5. An arrangement as claimed in claim 3, wherein said actuating means includes a spring for returning said actuating armature member to its normal position after said armature member has moved said selected yarn guide to said advanced position.

6. An arrangement as claimed in claim 1, wherein said selector member comprises a non-magnetizable material portion and has a magnetizable core portion; said electromagnetic selector means having Winding means receiving said core portion.

7. An arrangement as claimed in claim 1, wherein said selector member includes a shaft having a set of transverse bores, and a set of guide bushings respectively aligned with said bores, said yarn guides being respectively mounted in said bores and bushings for sliding movement along said second path.

8. An arrangement as claimed in claim 7, wherein said yarn guides have rear end portions projecting from said shaft and bores; comprising a spring mounted on each rear end portion and abutting the same and said shaft for urging said yarn guides to said normal position; and wherein said actuating electromagnetic means is adapted to move the selected yarn guide against the action of the respective spring to said advanced position.

9. An arrangement as claimed in claim 1, wherein said electromagnetic selector means includes a set of individually energizable windings disposed along said first path and having the same height, and wherein said selector member has a magnetizable core portion having substantially said winding height so that by successive energization of said windings said core portion and said selector member with said yarn guides is moved between said plurality of positions distances corresponding to said height for placing said selected yarn guide in said operative position; wherein said actuating means includes a set of spring means connected with said yarn guides, respectively, for urging the same into said normal position, and wherein said actuating electromagnet means includes an actuating armature member movable along said second path for moving said selected yarn guide in said operative position to said advanced position; comprising arresting means for arresting said selected yarn guide in said operative and advanced position while feeding a yarn so that said actuating electromagnetic means can be shortly energized, and for releasing said yarn guide when moved by said selector member out of said operative position so that the respective spring means returns said yarn guide to said normal position, said arresting means including a first catch projection on each of said thread guides, and a stationary second catch projection located in said second path to engage said first catch projection of said selected yarn guide when the same arrives at said advanced position so that when said selected yarn guide is moved by said selector member out of said operative position, said second catch projection thereof releases said first stationary catch projection.

10. An arrangement as claimed in claim 9, wherein said second catch projection is resilient and shaped so as to yield to said first catch projection during movement of the selected yarn guide to said advanced position.

References Cited UNITED STATES PATENTS 2,038,753 4/1936 Neininger 66--139 2,075,139 3/1937 Scheller. 3,232,079 2/1966 Levine et a1.

ROBERT R. MACKEY, Primary Examiner 

